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Premium Waterproofing Wood Stains & Concrete Sealers

The SEAL-ONCE Difference

Our Made in the USA wood sealers, deck finishes and tinted wood stains perform like oil-based products without any of the odor, toxic chemicals or harmful side-effects. They are water-based, ultra-low VOC, safer for the environment and will not harm people, pets, or plants.  SEAL-ONCE stains and sealers are low odor, easy to apply and cleanup with soap & water.

Quality We Stand Behind

Born of innovation in 2003, SEAL-ONCE is the leading brand of Eco-friendly, non-toxic, high-performance waterproofing wood sealers & deck stains. Our products are warranted to prevent long-standing water accumulation for up to 10 years on vertical surfaces and up to 6 years on horizontal surfaces. Please review the complete SEAL-ONCE Performance Guarantee details here.

Why Choose SEAL-ONCE?

Our proprietary nanotechnology provides superior, long-lasting protection from water damage by penetrating deep below the surface of wood, concrete & bricks. SEAL-ONCE bonds to cells at a microscopic level below the surface, unlike most film-forming, waterproofing deck sealers on the market today. Read about the power of nano-particles at The Science of SEAL-ONCE.


It was important to us to use an effective, eco-friendly, non-toxic sealer since the wood comes into contact with the roots of food crops, and children are exposed to it daily.

- Sara Fairchild, Parent/Garden Committee Volunteer, Mt. Washington Elementary School

What is most amazing about the end result, is that your product is invisible… You don’t know the roof has been treated, until it rains and you see the water beading again.

-Steve Oransky, Owner, Five Star Painting, Danvers, MA

The 20-year old mahogany deck was cleaned and sanded, then sealed with two coats of SEAL-ONCE with your semi-transparent mahogany tint. The results were amazing and the customer is thrilled!

-Richard McLaughlin, South Yarmouth, MA

Common Wood Applications:

Concrete & Masonry Applications:

  • Wood Decks
  • Ipe Decks
  • Pool Decks
  • Fences/Pergolas
  • Wood Siding
  • Cedar Shingles
  • Boat Docks
  • Railings & Beams
  • Play Structures
  • Log Homes/Cabins
  • Outdoor Furniture
  • Walkways
  • Steps
  • Brick
  • Stamped Concrete
  • Slate
  • Patios & Pool Decks
  • Pre-Cast Pavers
  • Sandstone
  • Mortar & Grout
  • Concrete Block



In 2016 SEAL-ONCE® was acquired by U-C Coatings, Inc., a leading manufacturer of wood protection products for the hardwood and softwood industries since 1971.  With the addition of SEAL-ONCE we are leading the innovation in nanotechnology to produce the highest quality water-based, ultra-low VOC wood sealers, wood stains & wood finishes available in the world today.


Our Location

U-C Coatings, Inc.

2250 Fillmore Ave.

Buffalo, NY 14214

Phone: (716) 833-9366

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